Rotary disk drill



- April 10,1928.

H. H. HOLDAWAY ROTARY DISK DRILL Filed Au -.26, 1925 Patented Apr. 10, 1928.

UNITED STATES HALL ir-notmwar, or saw'rmu, cat roanm norartrmsir DRILL- Application filed August as, 192's. Serial No. 52,534.

This invention relates to rotary disk drills and particularly to the type of bit which has one or more forks projecting downwardl from the shank of the bit and carrying dis cutters. These bits usually have two such forks with a disk attached to the inner face ofeach fork. In such a bit, it is desirable for the forks to be of reduced width at their lower ends, but if they are considerably reduced in this way, there is insufiicientbear ing surface for the rotary disk. It has also been common practice in the construction of such bits to provide a bolt through the.

lower end of the fork for securing the disk or its pin'in place; this necessitates an opening through the lower end of the fork which considerably reduces its strength at this point.

The general object of thisinvention is to provide a simple construction for a drill bit which will overcome these difliculties and which will enable the dimensions of the lower end of the fork to be considerably reduced without reducing the strength of the fork, and at the samev time, providing ample bearing surface for the rotating disk; also to provide simple means for securing the disk to' the the fork which will eliminate the necessity for drilling through'the lower end of the fork.

In the use of such cutter disks, the edges frequently become worn so far that the continued rotation of the bit in the hole will cause injury to other parts of the bit. One of the objects of this invention is to provide a construction for the disk which will prevent this and which' will render the disk useless as a cutter before it can incidentally cause any injury to the other parts of the bit.

One of the advantages of reducing the dimensions of the lower ends of the forks of the bit is that it not only reduces the weight of material in the bit but it also increases the-clearance in the hole.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an efficient rotar disk drill.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

- for the cutter disk 4.

In the drawings: i i

Fig. 1 is a side elevation of a bit embody: ing my invention, the upper portion of the bit being broken away.

Fig. 2 is aside elevation of the bitwith the, upper; portion broken away and showing the lower end of one of the forks and its cutter disk in cross-section. 1

Fig. 3 is an elevation showing the inner face of the disk and the lower end of the fork as viewed from the plane of the line 33 inFig. 2, the upper portion of the fork being broken away. TlllS view particularly illustrates a locking-device which I prefer to employ for holding the cutter disk on the fork.

Fig. 4 is a plan of a locking-plate which constitutes a feature of the locking-device for the cutter disk.

In practicing my invention, I rovide a rotary disk drill havin a shan with a downwardly extendin ork; this fork is preferably constructe with a Pin on its inner face; the width of the lower end of the fork in this bit is greatly reduced so that the width of the fork is actually less than the width of the bearing for the cutter disk. In order to provide a proper bearing surface for the cutter disk, I provide a bearing-washer at the inner face of the fork, and the disk cutter is mounted to rotate. on this washer; any suitable means may be employed for retaining the cutter on the fork, but I prefer to employ a locking-device in conjunction with a centrally disposed collar which retains the disk against the. washer and also secures the collar to the fork.

Referring more particularly to, the embodiment of the invention illustrated in the drawing, 1 represents the shank of the drill bit, provided with a water passage 1. The lower end of this shank is formed into two oppositely disposed forks 2. As illustrated in Fig. 1, it will be noted that the lower ends of these forks are of reatly reduced 100 width, that is to say, the foiis taper downwardly to their lower ends, and the width of the fork at the lower end is actually insuflicient to provide a proper bearing-face However, according to my invention, I provide means for providing this hearingface and for properly supporting the cutter disk. The preferred construction for this purpose is illustrated in detail in Fig. 2. I

provide the inner side of the fork with a pin 5, which may be constructed as an integral part of the fork.

At the inner face of the fork, I provide a washer 6 and on the pin I provide means for retaining the washer on the fork, and for retaining the'disk 4 on the washer. .In

order to accomplish this, I provide threads onf'the' outer side of the pin through the medium of which I secure a collar 7. The end of this collar is formed with a rabbet groove 8 which engages the opening in the washer and centers the same, and the shank -9 of this collar abuts against the inner face of the washer and .clamps the same against the face of the fork. y

The disk 4 is provided with a counterbore or annular rabbet groove 10 which receives the outer portion ofthe washer, so that the washer operates as a bearing for the disk, that is to say, it centers the disk and takes the thrust of the disk incidental to the cutting operation which occurs when the bit is rotated on its longitudinal axis.

I The collar 7 is preferably provided with a projecting head 11 at its inner end --presenting a conical face 12, which seats against a corresponding conical counter-bore on the inner face of the disk. In other words, the. head 11 is countersunk into the disk.

This leaves the inner face of the disk sub-- I stantially unobstructed and facilitates the these sockets a spanner wrench may be applied to screw the collar 7 home.

I prefer to utilize these sockets 11 ,to lockthe collar 7 in place; that is to say, they cooperate with a locking means; this locking means is preferably constructed so as to enable it'to engage with the sockets in the different angular positions the collar may assume. For this purpose, I provide a transverse slot 13 in the end face of the pin 5 in which is received a locking-plate 14. This locking-plate is held in place by a machine screw 15 which is threaded into the center of the pin.

The plate has a finger 16 at each end to fit into the notches, and these fingers are offset from the central axis of the plate so as to enable the plate to be turned over and applied in a reversed position. In this way, the finger can be used in either of two positions. This enables the finger to reach the same socket in two different angular positions.

In using bits of this type, there is a tena bushing threaded to said dency for drillers to use the bits until the edges of thedisks are worn away so far that the use of the bit endangers the other working parts of the bitat 'the forks. In order to prevent this, I form the disk with a pronounced shoulder 17 on the outer face of the disk and from this pointfout the body of the disk is in the form of a relathe sides and lower end ofthe fork. This gives ample bearing for the disk, although the fork is greatly reduced in width at its lower end. i

It i understood that the embodiment of the invention described herein is only one of the many embodiments this invention may take, and I do not wish to be limited in the practice of the invention, nor in the claims, to the particular embodiment set forth.

What I claim is:

1. A rotar disk drill having, a shank with a downwar ly extending fork with an integral threaded pin onits inner face, a disk cutter, a washer between the disk cutter and the inner face of the fork and constituting a bearing for the cutter, a collar received on the threaded pin having means for retaining the washer on the fork and having means for retaining the cutter on the washer, said collar having a plurality of spaced circumferentially disposed sockets on its inner face, a locking-plate with means for securing the same at the inner end of the pin, said locking-plate having a finger to co-operate with one of said sockets to lock the collar in place, said finger being offset from the axis of the plate whereby the locking-plate may be attached in a reversed position to co-op eratewith a socket in a different angular position. k Y I 2. A rotar disk drill for well drilling comprising a 0d having a downwardly exten ing fork an an axial flushing assage discharging between said fork, a p urality of disk cutters, means for revolubly mounting thedisk cutters on the body between the fork and spaced apart, said means including for each cutter a pin inte 'ralwith the body, pin and provided with an outer cutter retaining flange, said bushing being further provided with a circumferential series of sockets on its outer face, said pin having a transverse groove in its end, and a lockin' member in said groove and extending therefrom to said sockets, thereby 'forrnin a positive lock be tween the in and bus ing by means substantially ush with the outer face of the bushing, whereby flushing fluid discharged from said passage has an unobstructed flow to the lower cutting edge of said cutters, and means for holding-said locking member to said pin.

3.. A rotary disk drill for well drilling, comprising a bod having a downwardly extending fork an an axial flushing passage discharging between said fork, a plurality of disk cutters, means for revolvably mounting the, disk cutters on the body between the fork and spaced apart, said means including for each cutter a pin integral with the body,

a bushing mounted on said pin and provided with an outer cutter retained flange, said bushing further being provided with a circumferential series of sockets in the flan e of said bushing and terminatingshort of the periphery ofsaid flange, said pin having a transverse groove in its end and a locking member in said groove extending therefrom into said sockets, thereby forming a positive lock between the pin and bushing by means substantially flush with the inner face of the bushing, whereby the flushing fluid dis charged from said passage has a substantially unobstructed flow to the lower cutting edges ofsaid cutters.

Signed'at Los Angeles, California, this 19th day of August, 1925.

. HALL H. HOLDAWAY. 

